To identify users detected through our Dashboard, you need to include the userID parameter in the requests you send to Greip. Let’s look at some examples to illustrate this: 
https://gregeoip.io/IPLookup?key=your-api-key&ip=1.1.1.1&userID=john@example.com

https://gregeoip.io/IPLookup?key=your-api-key&ip=1.1.1.1&userID=John
When you include the userID parameter in your requests to the Greip API, it allows you to identify and track fraudulent activities (found on the Events page) associated with specific user information such as user name, email address, phone number, and more.
Greip Dashboard - Real-time events page

Greip Dashboard - Real-time events page

IMPORTAN NOTEThere’s no need to pass the userID parameter when you send Payment Fraud Prevention request to Greip API, as the User Identifier will be retreived from the input data you already pass, like customer_email, customer_phone, or customer_id.